1. Field of the Invention
In general, the present invention relates to battery powered illumination lights. More particularly, the present invention relates to battery powered illumination lights that contain photoelectric cells so that the batteries of the lights can recharge during daylight conditions when the light is not in use.
2. Description of the Prior Art
Since Edison's invention of the light bulb, electric lights have been used to illuminate countless objects. However, until recently, most electric lights were limited to applications where there was a steady supply of alternating current. This is mostly due to the fact that prolonged illumination of any object with a sufficient amount of light energy requires a substantial supply of electricity. Portable, direct current electric lights, such as flash lights, produce bright light for only short periods of time. Consequently, battery powered lights are generally used only when needed and are typically not relied upon to illuminate any object for a prolonged period of time.
Recently, however, there have been many advancements in the technologies that effect battery powered illumination. Those technological advancements include improvements in batteries, light sources and photoelectric cells that can be used to recharge batteries. For one, batteries now exist that can produce high current flows for prolonged periods of time and are rechargeable. Some of the more advanced rechargeable batteries have a better than 1:3 use/recharge ratio. That is, for every three hours of recharging the battery experiences at a set amperage, the battery can produce more than one hour of uninterrupted charge at that set amperage.
Another improvement is that light emitting diodes (LEDs) now exist that can produce light just as bright as incandescent light bulbs but use less than a third of the power required by incandescent light bulbs.
Lastly, advancements exist in photoelectric cell technologies that enable small photoelectric cells to produce enough electricity to recharge a rechargeable battery.
Rechargeable batteries, modern LEDs and photoelectric cells have recently been combined in many different types of rechargeable light assemblies to provide illumination at night. Such lights are used in applications where AC electrical power is not present, such as cemeteries, roadsides, and walkways. In each application, the batteries of the light charge during daylight hours and are used to illuminate lights at night. For a day with twelve hours of sunlight, many of these self-charging battery powered lights can generate light for up to five hours after dark.
Applications of self-charging battery powered lights are exemplified by U.S. Pat. No. 5,564,816 to Arcadia, entitled Illuminated Memorial Assembly, and U.S. Pat. No. 5,155,668 to Tanner entitled Solar Powered Lamp Utilizing Cold Cathode Fluorescent Illumination And Method Of Facilitating Same.
Of the prior art battery operated lights that recharge with solar power, they all share one common characteristic. That common characteristic is that the lights are intended to be placed outside. This exposes the photoelectric cells to sunlight during the day so that the batteries of the light can recharge. For lights that are used indoors, solar rechargeable lights are rarely used. This is because AC power is commonly available indoors and there typically is not enough ambient light indoors to provide the power needed to fully recharge a set of rechargeable batteries.
Indoor lights that do rely upon solar cells to recharge typically have very large areas of photoelectric cells to collect as much light energy as possible. The photoelectric cells are typically positioned near the light source so that when the light source is illuminated, some of the light energy produced can be received by the photoelectric cells and reused in the production of power. Such prior art lights are exemplified by U.S. Pat. No. 4,816,970 to Garcia, entitled Solar Powered Light.
In an indoor environment, there exist many applications for a light in places where there is no readily available AC power. It would be beneficial to provide a battery powered light in such applications, provided the battery powered light can be self-charging and thus not require a constant supply of fresh batteries. The object of this invention is therefore to create an improved self-charging light for indoor use.